Bicycle.



Y Patented Oct. 10, I899. B. -P. AMBLER.

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7 (Application filed Dec. 12, 1898.)

( No Model.)

INVENTOVR JRQ HMM &

WlTNESSES:

--ATTORNEY.

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UNITED STATES PATENT OFFICE. Y

RUSSELL P. .AMBLER, OF DE FUNIAK SPRINGS, FLORIDA.

- 'BICYICL'E.

SPECIFICATION-formingpart of Letters Patent No, 634, 789, dated October 10, 1899.

Application filed December 12,1898. Serial No. 699,033. (No model.) I i To (1% whom; it may concern:

Be it known that LRUssELL'P. AMBLER, a citizen of the United States, and a resident of De Funiak Springs, in'the county of Walton and State of Florida, have invented certain new and usefullmprovementsin Bicycle Driv lug-Gear; and I do declarethe following to be afulhclear, and exact description of the in vention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being bad to the accompanying drawings, and to letters of reference marked thereon, which form a part of this specification. Figure l of the drawings is a side elevation of a portion of a bicycle having my invention applied thereto. Figs. 2, 3, 4, 5, and 6 are detail views showing portions of the parts of my device at different points in the stroke.

This invention has relation to certain new and useful improvements in bicycle driving mechanism, and is more particularly designed as an improvement upon the driving mech-' anism described and claimed in my Patent No. 609,722, issued August 23, 1898.

The particular objects of the present invention are, first, to provide for a more efiective leverage to carry the cranks past the vertical centers, and, second, to so arrange the sup plemental foot-levers that their relation to the pedal-levers remains-unchanged during the entire stroke.

of the pedalrlevers, and F the fulcrum-arms for the lovers D, said arms having at their lower portions. oblong slots f, which are inclined upwardly and rearwardly and which loosely engage stationary pins 'or studs g, which are carried by rigid arms G, which depend from the hub or hanger A in a perpendicular line. The said pins or studs are preferably about six inches below the crank-shat t center; but this distance may be varied.

The supplemental leversEare rigidly secured to'the pedal-levers D and have downwardly-extendin g end portions E, which project below the pedal-levers and are designed in certain positions to take a bearing against the fulcrum-arms F below the points of pivotal connection of the latter with the pedallevers, as shown in Figs. 2 and. 3. The folcrum-arms F are provided with extensions F above the pedal-levers, and these extensions in certain positions of the levers are arranged to be impinged upon bythe rear portions of the supplemental levers E, as shown inFig. .5. The cranks G, pedal-levers D, supplemental levers E, and fulcrum-arms F exist in duplicate upon the two sides of the machine, the two cranks 0 being onehundred and eighty degrees from each other. The free end portions of the levers E terminate over the pedals and are provided with suitable pads for the foot, as in my said patent.

P designates the sprocket chain and gear, which connects the pedal-shaft with the hub of the rear driving-Wheel R. Any'suitable gear connection may, however, be employed.

The operation is as followsz Fig. 2 shows the pedal-lever on the downstroke, with the crank G at a position of aboutthree hundred and forty degrees, the fulcrum-arm F being substantially perpendicular with the pin or stud g at the higher end of the slot f. In this position the pedal-lever is nearly at the limit of its efiective stroke, while the crank has yet. to pass the top center before the pedal-lever begins its up movement. At this time the end portion E of the lever E below the pointX of pivotal connection of said arm with the lever E, and thereby pushes the lower arm of said lever rearwardly, the slot f riding on the pin or stud g until the lower end of the slot strikes said pin or stud. During this movement (the pressure on the pedal being continued) the crank is carried past the center and the fulcrum-point X is moved upward and forward to an extent equal to the upward and forwardmovement of the clination of the slot f being sufiicient to give takes a bearing against the fulcrum-arm F end of the crank in passing center, (the inthis amount of vertical moveinent,) the effect of the movement of said fulcrum-arm being to provide a new and changing fulcrum for the lever D during this part of its downstroke. The upstroke now commences, the rider pull ing upward with his foot on the lever E, and the crank moves forward and downward. Fig. 3 shows the position of the parts at this time. During this stroke the fulcrum-arm F and fulcrum-point X assume successively the positions shown in Figs. 4 and 5. When the parts are in the position shown in Fig. 5, the pedal leverv D has nearly reached the limit of its upstroke and the crank is approaching the lower center. At this time the rear portion of the lever E comes in contact with the extension F of the fulcrum-arm F above the fulcrum-point X, and thereby forces the lower portion of said lever forwardly, carrying the fulcrum-point X down wardly and rearwardly and the crank past the center. The position of the parts at this time is as shown in Fig. 6.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. In a bicycledriving mechanism, the combination of a shaft having cranks, pedal-levers connected to said cranks, fulcrum-arms to which said pedal-levers are intermediately fulcrumed, and which at their lower portions have a shiftable pivotal connection with the frame, the supplemental levers or arms connected to the pedal-levers and terminating at their free portions adjacent to and above the pedals thereof, and means whereby said fulcrum-arms are shifted at certain times, substantially as specified.

2. In a bicycle driving mechanism, the combination with a shaft having a crank, of a pedal lever connected at one end to said crank, a supplemental lever or arm connected to said pedal-lever and having its free end portion terminating aboveand adjacent to the pedal thereof, and its opposite end extended below the pedal-lever, and the fulcrum-arm shiftably connected to the frame at-its lower portion and to the upper portion of which the pedal-lever is fulcrumed, said fulcrum-arm and supplemental arm or lever being relatively arranged whereby their end portions will impinge upon each other in two difierent positions to thereby shift said fulcrum-arm, substantially as specified.

3. In a bicycle driving mechanism, a cranked shaft, a branched pedal-lever, one branch of which is arranged to receive downward pressure of the foot and the other branch upward pressure of the foot, and an arm shiftably and pivotally connected to the frame at its lower portion and to the upper portion of which the pedal-lever is fulcrumed, one branch of said pedal-lever being arranged to impinge upon said arm and shift the same at certain points in the movement of said lever, substantially as specified.

In testimony whereof I affix my signature in presence of two witnesses.

RUSSELL I. AMBLER.

Witnesses:

H. S. WILLIAMS, E. R. SPRAGUE. 

